#include <cstdio>
#include <cstdlib>
#include <iostream>
#include <cmath>

using namespace std;

const double zero=1e-8;

struct point{
	double x, y;
	point( double xx=0, double yy=0 ){
		x=xx; y=yy;
	}
	point operator +( point &b ){
		return point( x+b.x, y+b.y );
	}
	point operator -( point &b ){
		return point( x-b.x, y-b.y );
	}
	double operator *( point &b ){
		return x*b.x+y*b.y;
	}
	point operator *( double t ){
		return point( x*t, y*t );
	}
	double operator /( point &b ){
		return x*b.y-y*b.x;
	}
	point operator /( double t ){
		return point( x/t, y/t );
	}
};

double sqr( double x ){
	return x*x;
}

double dist( point a, point b ){
	return ( sqrt( sqr(a.x-b.x)+sqr(a.y-b.y) ) );
}

struct circle{
	point cp;
	double r;
	circle( point a, point b ){
		cp=(a+b)/2;
		r=dist( a, b )/2;
	}
	circle( point a, point b, point c ){
		double A,B,C,D,E,F;
		A = 2 * a.x - 2 * b.x;
		B = 2 * a.y - 2 * b.y;
		C = a.x*a.x + a.y*a.y - b.x*b.x - b.y*b.y;
		D = 2 * a.x - 2 * c.x;
		E = 2 * a.y - 2 * c.y;
		F = a.x*a.x + a.y*a.y - c.x*c.x - c.y*c.y;
		cp.x = (C * E - B * F) / (A * E - B * D);
		cp.y = (A * F - C * D) / (A * E - B * D);
		r = dist( a, cp );
	}
	circle( point a, double b ){
		cp=a; r=b;
	}
};

bool isin( circle a, point b ){
	if ( dist( b, a.cp )-a.r>zero ) return false;
	return true;
}

circle ans(point(0,0),1);
int n;
point pp[100010];

void random_data(){
	for ( int i=0; i<n; i++ ){
		int j=rand()%n;
		point t=pp[i]; pp[i]=pp[j]; pp[j]=t;
	}
}

int main(){
	int test=0;
	scanf("%d", &test);
	while ( test-- ){
	ans=circle(point(0,0),1);
	scanf("%d", &n);
	for ( int i=0; i<n; i++ )
		scanf("%lf %lf", &pp[i].x, &pp[i].y);
	random_data();
	for ( int i=2; i<n; i++ )
		if ( ! isin( ans, pp[i] ) ){
			ans=circle( pp[0], pp[i] );
			for ( int j=1; j<i; j++ )
				if ( ! isin( ans, pp[j] ) ){
					ans=circle( pp[i], pp[j] );
					for ( int k=0; k<j; k++ )
						if ( ! isin( ans, pp[k] ) )
							ans=circle( pp[i], pp[j], pp[k] );
				}
		}
	printf("%.2lf\n", ans.r);
	printf("%.2lf %.2lf\n", ans.cp.x, ans.cp.y);
	}
}
